The present invention relates to a semiconductor device and a method for fabricating the semiconductor device, more specifically, a logic semiconductor device combined with a non-volatile memory and a method for fabricating the same.
Logic semiconductor devices combined with non-volatile memory devices form product fields, as of CPLD (Complex Programmable Logic Device) and FPGA (Field Programmable Gate Array), and because of their characteristic of programmability, so far have formed large markets because of their characteristic, programmability.
The logic semiconductor device combined with a non-volatile memory has, in addition to flash memory cells, high-voltage transistors for controlling the flash memory and low-voltage transistors for the high-performance logic circuit integrated on the same semiconductor chip. The flash memory cell has a stack gate electrode structure including a floating gate and a control gate, which is different from the single gate electrode structure of the high-voltage transistor and the lower-voltage transistor. Accordingly, the logic semiconductor device combined with a non-volatile memory has the characteristic fabrication processing of forming the single gate structure and the stack gate structure in the same process.
The related arts are described in e.g., Reference 1 (Japanese published unexamined patent application No. 2001-015753) and Reference 2 (Japanese published unexamined patent application No. 2003-243620).